In the course of their work, firefighters are routinely exposed to a variety of carcinogenic substances, such as benzene, polycyclic aromatic hydrocarbons, formaldehyde, and asbestos. There is substantial evidence indicating that firefighters are at increased risk for bladder, brain, and lymphohematopoietic cancers. Excess mortality for cancer of the lung, kidney and ureter, rectum and colon, and skin has also been reported. Because most of previous firefighter cancer studies are based on mortality data, the full extent of firefighters' cancer risk, in particular, incident cancer risk and risk for rare cancers, is not yet known. To date, there is only one published standardized incidence ratio study of firefighting and cancer. Furthermore, cancer incidence or mortality studies have not been undertaken among Florida firefighters. The proposed study will be a retrospective analysis of cancer incidence and mortality among a cohort of state-certified Florida male and female firefighters. Beginning in 1972, all firefighters were required to become certified in order to work in the State of Florida. A database containing over 42,000 computerized firefighter certification records from 1972-1998 will be provided to the investigators by the Florida Fire Marshals Office. Information from this database will be linked to the Florida Cancer Data System and incident cancer cases among the cohort will be identified. Vital status will be determined by linking the firefighter database with the Florida Motor Vehicles database and Florida Pension Records database. Mortality information will be obtained by linking the firefighter database with the Florida Vital Statistics database. For those firefighters not found through these four data linkages, ChoicePoint (formerly known as Equifax) Nationwide Death Search will be used to ascertain their vital status. Standardized incidence ratios and standardized mortality ratios will be calculated using the general Florida population as comparison for overall and site-specific cancers to determine whether Florida firefighters have excess risks for these cancers. This proposed study will be the largest cancer incidence study to date. Results from this study will add to the body of knowledge concerning firefighting and incident cancer risk, particularly for low-fatality cancers and rare cancers, and provide data needed for further studies of firefighting exposures and site- specific cancers, as well as prevention-intervention studies.